DES MOINES, Iowa (AP) — It’s been a different presidential race in Iowa this year — quieter.

Campaign headquarters have hardly been buzzing with activity, unlike the around-the-clock nature of past contests. Candidates have barely visited the state, compared with years when most all but moved here. And they have largely refrained from building the grass-roots armies of yesteryear, in favor of more modest on-the-ground teams of paid staffers and volunteers.

The final rush of campaigning here gets under way Monday, just a week before the Jan. 3 caucuses, and, to be sure, there will be a flurry of candidate appearances and get-out-the-vote efforts all week.

But that will belie the reality of much of 2011, a year marked by a less aggressive personal courtship of Iowans in a campaign that, instead, has largely gravitated around a series of 13 nationally televised debates, a crush of television ads and interviews on media outlets watched by many Republican primary voters, like Fox News Channel.

“We just haven’t had as much face time,” Republican chairwoman Trudy Caviness in Wapello County said. “That’s why we’re so undecided.”

Indeed, people here simply don’t know the Republican presidential candidates that well. And it’s a big reason why the contest in Iowa is so volatile and why the caucus outcome could end up being more representative of the mood of national Republicans than in past years when GOP activists here have gone it alone by launching an unlikely front-runner to the top of the field.

With a week to go, the state of the race in Iowa generally mirrors the race from coast to coast.

Polls show Newt Gingrich, the former House speaker, having lost ground and Texas Rep. Ron Paul having risen, with both still in contention with former Massachusetts Gov. Mitt Romney at the head of the pack. All the others competing in Iowa — Texas Gov. Rick Perry, Minnesota Rep. Michele Bachmann and former Pennsylvania Sen. Rick Santorum — are trailing.

But, in a sign that the contest is anyone’s to win, most polls have shown most Republican caucusgoers undecided and willing to change their minds before the contest in a state where the vote typically breaks late in the campaign year.

There are a slew of reasons why the Iowa campaign is a much more muted affair than in 2008 — marked by the iconic clash of Barack Obama and Hillary Rodham Clinton, who together employed almost 300 staff in Iowa and held blockbuster rallies. This year, there is no contested Democratic primary, given that President Barack Obama has no serious challenger. Only Republicans are competing, and those candidates are approaching the state differently, both visiting and hiring less. Also, like it did everywhere else, the race here started slowly — months later than usual — as a slew of GOP politicians weighed candidacies, only to abort White House bids.

Long-time Republican activists here, who often joke that they like to meet the candidates several times before deciding, have barely seen the candidates once, much less at all, and no campaign has more than 20 paid staff in the state.

All that’s partly a consequence of how technology has changed both the political and media environments in recent years. Campaigns now can more precisely — and cheaply — target their pitches to voters from afar, sending personalized e-mails and YouTube video messages from the candidates to voters directly, and more campaign outreach is being handled by volunteers and through central national websites. And voters, themselves, now can go online and find information about the candidates without having to wait for the White House hopeful to show up in the town square.

“Caucuses don’t exist in a vacuum. They’re not the same every time,” said John Stineman, a West Des Moines Republican activist who ran Steve Forbes 2000 Iowa campaign. “But everything else has changed. Why wouldn’t the caucuses change?”

Part of the change has been driven by Romney’s approach to the state.

The nominal GOP front-runner for most of the year, Romney has been far less aggressive in cultivating support in Iowa than in his failed bid of 2008. He’s only spent 10 days in the state this year, compared to 77 days four years ago, in an attempt to lower expectations in the leadoff state where evangelical conservatives have harbored doubts about Romney in light of his Mormon faith and changed positions on some social issues.

Paul, the Texas congressman, has been focused more on building a national following than being a one-state candidate.

Gingrich only became a serious contender in the state a few weeks ago. And, until recently, he didn’t have the money or manpower to launch a full-scale Iowa campaign, meaning more sporadic visits and a smaller team. He’s struggled to reach all parts of the state more than once; it was just last week that he visited Ottumwa, seat of the county Caviness represents and a medium-size Iowa city uniquely situated in the southeast with its own small media market.

Likewise, Perry has not been to Marshalltown, a central Iowa GOP hub about the same size as Ottumwa and home of the state-run veterans home. It would seem like a natural spot for Perry, a former Air Force officer who has sought veterans support. But he also hasn’t visited Fort Dodge, also another mid-size Iowa city in north-central Iowa on the way to heavily Republican northwest Iowa.

Those who have been struggling to gain traction — and who lack the money of better-funded, better-known rivals — are turning to old-fashioned retail campaigning in hopes of wooing voters the traditional way.

Bachmann is in the midst of a bus tour that has her crisscrossing the state. And Santorum, who never has broken out of the back of the pack, is betting that a year of one-on-one campaigning will pay off in the end.

Barb Livingston is proof that, for all the changes, there’s still something to be said for the personal approach. She has struggled all year to find a candidate to back and is basing her decision on a personal impression she had — except that impression was established four years ago, riding around Marshall County with Romney.

“When push comes to shove, I had a chance to meet him and travel around with,” said Livingston, a former Marshall County GOP chairwoman. “He’s someone personally I connected with.”